This invention is directed to a hand-display electronic timepiece, and in particular to a hand-adjustment mechanism adapted to position the second hand of an electronic timepiece in a predetermined advanced position in response to the operation of the hand adjustment mechanism.
Heretofore, mechanisms for adjusting the second hand in electro-mechanical wristwatches have taken on various forms. For example, adjustments of .+-.0-1 seconds or .+-.n seconds, where n=1, 2,3 . . . by selectively displacing a winding stem have been provided. When the displacement of the winding stem effects a .+-.0-1 seconds second hand adjustment, seconds correction can only be effected when the second hand is in advance of actual time by either advancing the second hand at one second increments until the second hand is correctly positioned, and thereafter rotating the minute hand at least one entire revolution or by holding the second hand stationary until the position thereof is at or behind actual time. Moreover, if the second hand is slow by more than one second, repeated displacement of the winding stem is required in order to advance the second hand a sufficient number of one second increments to place same at a correct position. Since accurate information for setting a timepiece is usually given in ten second increments (radio, television and telephone) such repetitive advancing of the second hand does not always provide accurate adjusting of the second hand.
The second type of adjustment, namely, adjusting the second hand by .+-.n seconds is also less than completely satisfactory. For example, if the second hand is slower than or in advance of the .+-.n second increment by more than n seconds, repetitive displacement of the winding stem will not effect proper adjustment. Specifically, if a two-way cam is utilized to position the second hand, .+-.n seconds, there is no assurance as to whether the second hand will be advanced or moved back by the .+-.n increment. Even if the proper direction is achieved on the first displacement of the winding stem, a displacement of the winding stem immediately thereafter will effect a rotation of the second hand back to the position to which same was first displaced by the preceding displacement of the winding stem. Accordingly, two-way positioning of the second hand at increments of .+-.n seconds provides a less than completely satisfactory second hand adjustment mechanism.